Time-Shared Time-of-Flight Analysis by Computer

Abstract

A time-shared computer-centered data collection system has been placed into operation at the Brookhaven Graphite Research Reactor. The system provides simultaneous data collection and sorting for two physically unrelated neutron time-of-flight experiments in time-share with a general computation facility. A general purpose stored-program digital computer with a 4096 word, 24-bit memory is the heart of the system. The computer system provides, for the ``fast neutron chopper'' experiment, a 1024-channel time analyzer for total or partial neutron cross section experiments, three elapsed-time clocks, three total events scalers, two monitor scalers, and a chopper tachometer. At the same time, for the ``slow neutron chopper'' experiment, the system provides a 256-channel time analyzer, a clock, a total events scaler, a monitor scaler, and a chopper tachometer. The two experiments are independent of one another and are controlled by the typing of four-letter mnemonic codes on the system typewriter. A live cathode-ray tube display of either experiment is present at all times except when the time-shared computational facility is being used. Connections between the computer and the external analog-to-digital converters are made on a patchboard, allowing convenient control of data format. The system has been designed to facilitate expansion to multiparameter data handling.